Albert l



(NO Model.)

A. L. REINMANN. INGANDESOENT ELECTRIC LAMP.

N0. 460,991. Patented Oct. 13, 18.91.

m N m m WITNESSES Z/Qf A TTORNEYS ms mm KTLRS c04 mow-mum, msumc'mu u cUNITED- STATES PATENT OFFICE.

ALBERT L.

REINMANN, OF NEIV YORK, N. Y., ASSIGNOR TO THE ESTING- HOUSE ELECTRICAND MANUFACTURING COMPANY.

INCANDESCENT ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 460,991, dated October13, 1891.

Application filed February 11, 1891- Serial No. 381,025. (No model.)

To all whom it may concern:

Be it known that I, ALBERT L. REINMANN, of the city, county, and Stateof New York, have invented a new and useful Improvement in IncandescentElectric Lamps, of which the following is a specification.

A large item in the expense of making incandescent electric lamps is thecost of the platinum wire which is used to form the lead- IO lug-1nwires of the lamp. The platinum is used for those portions of theleading-in wires which aresealed in the glass because its co-efficientof expansion and contraction is nearly the same as that of glass. It isvery desirable to reduce the amount of platinum as much as is consistentwith the making of a proper joint between the bulb and the leading-inwires, and my invention is directed to effecting a saving in thatparticular. It is especially :0 useful in the manufacture of large lampswhere long leading-in wires are necessary.

To enable others skilled in the art to make and use my invention, I willnow describe it by reference to the accompanying drawings,

in which Figure 1 is a sectional view of a large incandesceut lamp, andFig. 2 is a view of the leading-in wires partially secured in the glassstem or support in which they are fused.

0 Like letters of reference indicate like parts in each.

The part of the lamp which contains the leading-in wires and supportsthe carbon conductor or filament is made separately from the bulb, andin this separated condition is called a mount. I show a mount in Fig. 2in a partially-completed condition. The lead ing-in wires are composedof a section a of copper wire, a section b of platinum, a sec- 0 tioncof copper wire, and a section (I of platinum. The platinum section b issurrounded by a piece of glass 6, which is fused around the two wires,and this portion in the completed lamp closes the open end of the bulb 5or globe f, the open end of the bulb being fused to the glass part 6, soas to hermetically seal the bulb. The copper section 0 is surrounded bya small glass tube g, which is sealed at the upper endaround theplatinum section cl, so that the copper section 0 when inserted in thelamp shall not be exposed to the inside of the lamp, the object being toprotect the carbon conductor from the action of any oxide which might bepresent upon the surface of the carbon wire. Upon the sides of the glasstubes g are formed small openings or tubes h. The glass tubes g areplaced over the leading-in wires and first fused to the glass part c, asshown in Fig. 2; Then the upper ends are fused to the plati- 6o nunrsections d, the tubes 71 being open to prevent the increased pressure ofthe air inside of the tubes occasioned by the heating of the ends insealing to the platinum wires from acting upon the soft glass at thejoint and thereby preventing a tight and permanent joint from beingmade. After the glass has cooled at the ends the tubes 7L are closed up,so as to hermetically seal the copper wires inside of the tubes. Thenthe carbon cou- 7o ductor i is secured tothe platinum sections (1 in anywell-known way, and the mount is completed and is inserted into the bulbf and secured thereto in the ordinary way. In this way I produce a lampin which those portions 75 of the leading-in wires which pass throughthe glass are composed of platinum, thereby insuring tight joints withthe glass, and those portions which are required only for conductingpurposes are formed of asuitable cheaper metal, such as copper,aluminium, or German silver.

IVhen I speak in the claims of copper wire,

I include other cheap suitable conductors as equivalents.

The small tubes or openings it necessary to vent the tubes g duringprocess of sealing them on the platinum sections may be formed eitherbefore the tubes are placed over the wires or after they have beenplaced over them and secured to the glass post c by heating the sides ofthe tubes 9 and drawing the tubes h out from the heated portions.

The copper sections a are the usual copper wires by which the lamp isconnected to its 5 base.

In my improved lamp I am able to dispense with the use of platinum inthat portion of the leading-in wires which extends from the lower seal 6up to a point near where the carbon conductorz is secured thereto, andthis saving in manufacture of large lamps is very considerable.

What I claim as my invention, and desire to secure by Letters Patent, is

1. The method ofmakingincandescent electric lamps having leading-inwires composed of two sections of platinum wire with an intermediatesection of copper wire, which consists in forming a glass seal aroundthe lower section of the platinum wire, surrounding the copper sectionswith glass tubes having ventopenings in the sides, then sealing theupper ends of the tubes around the upper platinum sections, then closingthe vent-openings, securing the carbon conductor to the leadingin wires,and sealing the mount so formed into the lamp-bulb in the usual way,suhstan tially as and for the purposes described.

2. An incandescent electric lamp the leading-in wires of which are eachcomposed of two separate sections of platinum wire with an intermediatesection of copper Wire, the platinum sections being sealed in the glassand the intermediate section of copper wire being inclosed in a glasstube, substantially as and for the purposes described.

In testimony whereof I, the said ALBERT L. REINMANN, have hereunto setmy hand this 30th day of January, A. D. 1891.

ALBERT L. REINMANN.

\Vitnesses:

THOMAS E. KERR, RoBT. F. GAYLORD.

